DM is an inherited neurologic disease typically affecting dogs around eight years of age or older. It causes gradual muscle wasting and incoordination in the hind limbs, and then progresses to an inability to walk after six to twelve months.
The progression of degenerative myelopathy can vary, it typically takes anywhere from 6 months to 3 years. The more advanced stages of mobility loss usually occur after the first year of diagnosis. In its final stages, degenerative myelopathy can spread to the brain stem.
Degenerative myelopathy (DM), also known as chronic degenerative radiculomyelopathy (CDRM), is a disease affecting the spinal cord, resulting in slowly progressive hind limb weakness and paralysis. The symptoms result from degeneration of the white matter of the spinal cord.
Degenerative Myelopathy is a neurodegenerative disease in dogs. Neurodegenerative means a progressive and often irreversible deterioration and loss of function of the nervous system, especially the neurons in the brain.
Dogs with DM may exhibit progressive weakness and lack of coordination in the hind limbs leading ultimately to paralysis. Euthanasia is required once the disease begins to impact breathing. DM is a type of autoimmune disease.
Chronic myelopathy can be caused by a tumor on or near the spinal cord, spinal stenosis, rheumatoid arthritis, or neurogenerative diseases such as amyotrophic lateral sclerosis (ALS) or Parkinson's disease.
While the pathophysiology of multiple sclerosis (MS) and degenerative cervical myelopathy (DCM) differs—MS via an autoimmune process and DCM by a mechanical compressive process—both are characterized by damage to myelin and have overlapping presentations (Hurwitz, 2009; Young, 2000a; Ulmer et al., 1993; Nouri et al., ...
DM may be painless, but most dogs with severe chronic pain will display no signs. Therefore, I have also seen cases of severe hip dysplasia, cruciate ligament rupture or arthritis get mistaken for DM. Degenerative myelopathy is described as a diagnosis by exclusion.
How long do dogs live with Degenerative Myelopathy? Dogs generally live with DM for anywhere between six months and three years. Rehab therapy and regular exercise can help improve the quality of life for dogs with DM. Unfortunately, Degenerative Myelopathy has no cure at the moment.
How Quickly Does Degenerative Myelopathy Progress? Unfortunately, DM tends to progress very quickly. Most dogs that have been diagnosed with degenerative myelopathy will become paraplegic within six months to a year.
Symptoms of Neurological Disorders in Dogs
Knuckling over of the feet. Unusual, rapid eye movements (nystagmus) Head tilt or circling. Difficulty walking.
14 Disorders that often mimic and coexist with DM include degenerative lumbosacral syndrome, intervertebral disc disease, spinal cord neoplasia and degenerative joint diseases such as hip dysplasia or cranial cruciate ligament rupture.
There are a number of specific physical tests that can be carried out to evaluate the functioning of the various components of the nervous system. These include tests of various reflexes, muscle function and control, and posture and gait. Laboratory tests are often needed to diagnose the specific problem.
Dogs with DM will struggle, which may be painful to watch, but they aren't experiencing any pain. This loss of strength and changes in a dog's mobility does place additional stress on a dog's body. Symptoms of DM come on slowly and are often very subtle and easily missed.
What are the long-term consequences of degenerative myelopathy? Unfortunately, degenerative myelopathy progresses to paralysis i.e. an inability for your dog to walk and support their own bodyweight. The progression of the disease results in further weakness, muscle atrophy and finally faecal and urinary incontinence.
Dogs suffering from degenerative myelopathy do not appear to be in pain, but they may show anxiety, frustration, or irritation as a result of their decreased mobility.
STAGE 4 – LMN tetraplegia and brain stem signs (~ over 36 months) – At the end of the disease, the degeneration can progress to involve neck, brain stem, and brain. Patients will not be able to move all four limbs, have trouble breathing, and have difficulty with swallowing and tongue movement.
Treatment for Degenerative Myelopathy in Dogs
Veterinarians may be able to treat some related symptoms to relieve discomfort, but a healthy diet and plenty of exercise, including walking and swimming, are the main ways to keep dogs with the condition as mobile as possible.
Degenerative cervical myelopathy is the most common spinal cord problem in people 55 years and older in the United States. If it is not treated, it usually stays the same or gets worse. There is no way to tell whether it will get worse.
MRI scans are the preferred diagnostic method for cervical myelopathy, but other methods can also be used to help rule out other conditions. Cervical myelopathy is best treated with spine decompression surgery.
Spinal cord lesions caused by canine degenerative myelopathy are undetectable on standard clinical MRI limiting our ability to diagnose and monitor the disease.
Background: Degenerative myelopathy (DM) in dogs is a progressive neurodegenerative condition that causes white matter spinal cord lesions. These lesions are undetectable on standard magnetic resonance imaging (MRI), limiting diagnosis and monitoring of the disease.
As cervical myelopathy presents with such a variety of symptoms associated with other conditions, it can often lead to a delay in diagnosis and, sometimes, misdiagnosis in primary care. For example, sciatica can mimic certain symptoms of cervical myelopathy in the lower limb.
Degenerative myelopathy in dogs most parallels the disease in ALS or Lou Gehrig's disease in humans. Like ALS, DM is not a painful disease. It affects mature dogs usually between the ages of 8-14 years. It is a slow progressive, non-inflammatory deterioration of the white matter of the spinal cord (1).